在 2011-7-23 晚上11:03，"Mike Pall" <email@example.com>写道：
> Xavier Wang wrote:
> > Is that difficult to make unresolved function name become nil?
> > ffi.C.foobar --> nil
> That's not difficult. But there would be no way you could get the
> error message then (a table lookup can only return one result).
> And you'd have to litter your code with asserts. It makes more
> sense to error out here. For a C program you'll get an error when
> the static or dynamic linker fails to resolve a symbol, too.
I see, maybe providing another function to lookup symbols is better ?
ffi.lookup("C", "foobar") -- nil, "no such symbol"